I recently played a game with Rebuild, Scouting Party and Mission (Provinces). I initially pursued the Rebuild strategy on this board without casting too much thought into the events at hand.
Eventually, I realised that I could buy Mission on four coin hands just to get back to Rebuild faster. However, there was the drawback that I couldn't buy cards on the Mission turns. Wait, I can buy events! How about another Mission? Nope, that doesn't work.
I'll get a Scouting Party; that should help get me back to my Rebuilds even faster. Wait again, I can buy more than one Scouting Party on these turns! Even more cycling. Not only that, but Scouting Party helps prevent drawing Rebuild with too many green cards (one of the more unpleasant things to see playing with Rebuild obviously).
Combined, these two events made the Rebuild plan much quicker that game. I think that Scouting Party is the more important of the two events mentioned. With 4 coin, you can go through 6 cards and pair Rebuild with a Silver, for example, which will at least buy you an Estate should you want it. Mission goes through less cards (4) but may let you play Rebuild(s) again in one turn.
Because, you know, Rebuild needed other cards/events to make it a strong option.
